Download Explain each step of the scientific method.

Explain each step of the
scientific method.
1. State the problem
•
This is a question that you want to answer
2. Collect and organize the data
•
Research the subject
3. Formulate a hypothesis
•
A hypothesis is a testable statement that will answer a
question.
4. Experiment
•
Test your hypothesis by using a control and experimental set
up.
5. Analyze and record data
•
Compare your results from each experiment to see if there is
evidence that supports your hypothesis.
6. State your conclusion
•
Accept or reject your hypothesis. If you reject your hypothesis,
create a new one based on your findings and re-experiment.
Differentiate between an
independent and dependent
variable in an experiment.
Independent Variable
(manipulated) – the factor that
will be manipulated or changed
during the experiment. This is
the variable being tested.
Dependent Variable (Responding)
– the factor that responds due to
the manipulation of the
independent variable. This is
what happens as a result of the
independent variable.
Explain the difference between a
hypothesis and a theory.
• A theory is logical tested explanation
for events that occur in nature that are
based on many consistent observations.
– The same hypothesis has be accepted over
and over and over again.
• A hypothesis testable statement that
predicts a possible answer to a question
What is the difference between a
control group and an
experimental group?
Control Group : This setup is part of an
experiment that receives no
experimental treatment. It is
identical to the experimental group,
except for the variable being tested.
Experimental Group: This group
receives experimental treatment. It
has the variable that is being tested.
What is a placebo?
• A placebo is a fake version of the variable
being tested (like a sugar pill) used to
make the participants of the experiment
“think” that they are receiving the real
variable being tested.
What is bias?
• Personal judgment that might alter the
results of an experiment.
• Prejudice
Explain the eight
characteristics of life.
1.
Composed of cells
•
2.
Cells are the basic unit of life and can by unicellular (one cell) or
multicellular (more than one cell)
Reproduce
•
3.
Reproduction is the process in which new individuals are
produced.There are two types: asexual (only one parent) and sexual
(two parents).
Based on universal genetic code
•
4.
DNA provides the directions for inheritance in every organism on
Earth.
Grow and develop
•
5.
Organism increases in mass. Unicellular organisms just get bigger;
Multicellular organisms increase in number as well as size.
Use energy and metabolize
•
6.
The sun is the source for all energy. Metabolism is the sum of all the
chemical processes in the organism.
Respond to their environment
•
7.
Respond to a stimulus (any change that can cause a reaction)
Maintain stable internal environment
•
8.
Homeostasis: produce energy and remove waste
Change over time (evolution)
•
Organisms must change to survive an ever changing world
Compare and contrast sexual
and asexual reproduction.
• Asexual – single parent gives rise to one
or more individuals (binary fission,
budding, fragmentation).
– Bacteria (binary fission); hydra (budding-buds
formed on the parent break away and grow
into a new organism); Sea Star
(fragmentation- new organism grows from a
fragment of the parent.)
• Sexual Reproduction – the joining of two
specialized sex cells (sperm and egg),
usually from different parents. Ex: humans
Compare gamete and gonad.
• The gonad is the organ that makes
gametes. The gonads in males are the
testes and the gonads in females are the
ovaries.
• Gametes are the sex cells. The gametes
in males are sperm and the gametes in
females are ova (eggs).
– Spores(in unicellular organisms) and pollen(in
plants) are also gametes
Compare compound microscope,
scanning electron microscope,
and transmission electron
microscope.
• Compound Light Microscopes:
– focus light rays that pass through the
specimen to produce a magnified image
• Transmission Electron Microscope (TEM):
– Shine a beam of electrons at a sample and
then magnifies the image of the sample onto
a fluorescent screen beneath the scope.
• Scanning Electron Microscope (SEM):
– Scans a beam of electrons back and forth
across the surface of the specimen. The 3-D
image is produced onto a screen.
Compare and contrast
magnification and resolution
• Magnification is making objects larger.
• Resolution is the ability to distinguish two
items as being separate.
Differentiate between an
element,compound, and a
mixture
• An element consists of only one type of
atom.
• Compounds are chemically combined
elements
• A Mixture a substance consisting of two or
more substances mixed together (can be
separated).
What is chemical bonding?
• Chemical bonding happens when atoms
from two or more different elements
combine to form a new substance
What is a polar molecule?
• One side of the molecule has more
positive charge than the other side.
• Ex: water molecule
Differentiate between ionic bond,
covalent bond, peptide bond, and
hydrogen bond
• Ionic bonds involve the transfer of electrons
from one atom to the other.
• Covalent bonds involves the sharing of
electrons between atoms (can be polar like
water)
• Peptide bonds form between amino acids to
form proteins.
• Hydrogen bonds are the weakest bonds
between hydrogen atom and an electronegative
atom like O, N, or F…found between the
nitrogen bases in DNA and RNA
Write the chemical equation for
photosynthesis and identify the
products and reactants.
Coefficient (number of molecules)
Subscribt (number of atoms)
6CO2 + 6H2O → C6H12O6 + 6O2
Energy
Chlorophyll
Reactants
Products
6CO2
Element
Carbon (C)
Oxygen (O)
Total
# of atoms
6
6*2= 12
18
What is unique about water’s
bonding characteristics and why
is it essential to life?
• Water is a polar molecule with a high
specific heat, which allows the Earth’s
surface temperatures to vary within limits
to allow living organisms to survive.
• Has the property of cohesion which allows
the water molecules to stick together to
have more structure than other liquids.
• Water is the universal solvent.